A trademark includes any word, name, symbol, or device, or any combination used, or intended to be used, in commerce to identify and distinguish the goods of one manufacturer or seller from goods manufactured or sold by others, and to indicate the source of the goods.  In short, a trademark is a brand name.

A service mark is any word, name, symbol, device, or any combination, used, or intended to be used, in commerce, to identify and distinguish the services of one provider from the services provided by others, and to indicate the source of the services.